Hosiery linking machine



Nov. 4, 1969 c. L. CONTI HOSIERY: LINKING MACHINE 4 Sheets- Sheet 1Filed Jan. 23, 1967 INVENTOR CBSARE L.

CONTI Nov. 4, 1969 C. L. CONTI HOSIERY LINKING MACHINE 4 Sheets-Sheet 2Filed Jan. 23, 1967 InvggioR CESARE 2.. CONTI Nov. 4, 1969 Filed Jan.23. 1967 Fig.3c

c. L. CONTI 3,476,064

HOSIERY LINKING MACHINE 4 Sheets-Sheet 5 INVENTOR czsmzn 1.. com: m?g-QRNEY HOSIERY LINKING MACHINE Filed Jan. 23, 1967 4 Sheets-Sheet 4-NVBNT CESAR! in CO A RNBY United States Patent Int. cl. D05b 7/00 US.Cl. 112-25 5 Claims ABSTRACT OF THE DISCLOSURE This machine has theconventional pin plate having impaling pins for holding the fabric whichis to be seamed. The needle is a hooked needle and is secured to aneedle bar that is oscillatable and reciprocable in a carrier that isoscillated about the axis of the plate to move the needle from oneimpaling pin to the next. A crank effects oscillation and reciprocationof a lever, which, through a universal joint connection and a secondcrank and pin connection, reciprocates and oscillates the needle bar tomove the needle toward and away from the pins and to effect its requiredrocking movement. This same lever is connected by a sliding pin and slotconnection with the needle bar carrier to effect the oscillation insynchronization with the movement of the needle bar.

This invention relates to a hosiery linking machine and to a process forlinking hosiery articles on the face.

Prior or contemporary art linking machines, which make single-threadloop stitches (Federal Bureau of Standards No. 101) are constructedaccording to two basic types, viz:

(1) Needle internal to the pin plate and blind hook external withrespect to the pin plate, in which the loop stitch is formed on theoutside face of the fabric, and

(2) Needle external to the pin plate and blind hook internal to the pincrown, in which the loop stitch is formed on the inside face of thefabric.

It is also known to those skilled in the art that, in a number ofpractical cases, for example on a smooth knitwork, in which the seamformed by the needles can be seen only from the outside face of theknitted fabric, it is convenient to impale the knitted fabric on thepoints or pins with the face of the fabric directed towards the outside.By so doing it is much easier and quicker to follow a straight line on asingle seam. Thus, in cases such as indicated above, it would be wiserto adopt linking machines of the kind listed under (2) above, a loopstitch being thus obtained on the reverse (inner) side of the knittedfabric.

It should be noticed, however, that the machines of the second typeindicated above are exposed to very serious drawbacks both of aconstructional and functional nature.

For example, if the needle becomes even slightly deformed it will bumpat high speed against the bronze pin plate, thus causing irremediabledamages, apart, of course, from slowing down operations and the highcost of repairs, since the mechanisms involved are sensitive andexpensive precision mechanisms. It should also be noticed that thesafety devices suggested in the past, which are not even mentioned herefor brevity, have all proven inadequate.

Finally, all those skilled in the art are aware that, with the prior andcontemporary machines, it is diflicult to exceed speeds in the order ofmagnitude of 500 stitches per minute, since the stresses imparted to thethread are often considerable and the high-grade yarns used have arelatively small tensile strength, thus requiring for example, theadoption of cotton yarn for linking cashmere garice ments, since thecashmere thread has a resistance which is insufficient to ensure thestitch formation even at reduced stitching speeds.

The main object of the present invention is to provide a linkingmachine, of the internal needle type, which is sturdy, inexpensive, andfree from the above enumerated drawbacks.

Another object of the present invention is to provide a linking machinehaving a needle internal to the pin plate, and which is capable ofoperating free from the shortcomings listed above, at speeds even in theorder of magnitude of 1500-4800 stitches per minute.

A further object of the present invention is to provide an improvedmethod for the formation of loop stitches in hosiery, said methodconsisting of an orderly sequence of operations for the formation of thestitches so as to achieve the advantages of safe and rapid operation asoutlined above.

Still another object of the invention is to provide a machine, Which iscomparatively simple from a mechanical and constructional standpoint,for putting into practice the above-mentioned method.

According to the present invention, in a hosiery linking machinecomprising a ring carrying impaling pins for impaling the fabric to belinked, a needle cooperating with said plurality of impaling pins andmounted internally of said ring, and a device for feeding and guidingthe thread cooperating with said needle and pins for the formation ofthe loop stitch, a stitch-forming device is provided which essentiallycomprises:

(a) A needle having at least a projecting gripping member adapted firmlyto grip the thread fed by said threadfeeding and guiding device;

(b) A needle-carrying member, consisting of a lever having a limitedangular stroke about a vertical axis located at the geometrical centerof said pin plate;

(c) A needle-bar borne internally to said needle-carrying member so asto be capable of sliding axially therein, thus allowing said needle barto rotate about its axis during a certain step of the stitch-formingsequence;

(d) A lever, underlying said needle-carrying member and cooperating withan eccentric which is driven by a prime mover internal of the machine soas to impart an axially translational motion to said needle-bar withinsaid needle-carrying member;

(e) A grooved block, positioned at the end of said lever near saideccentric, the groove in said block being directed parallel to the axisof said eccentric;

(f) A pin, having a spherical tip and slidable within said groove ofsaid block, and

(g) A crank solid with said pin at one end and solid, at the other end,to the end of the needle bar remote from the needle.

According to another important feature of this invention, a method isprovided for the formation of a loop stitch in a linking machine havingthe needle internal to the pin plate, said method comprising thefollowing sequence of movements imparted to the needle bar and thus tothe needle:

(A) Causing the needle to advance towards the pin plate from the insideto the outside, its hooked end pointing downwardly;

(B) Rotating the needle through about 45 degrees about its own axis sothat its hooked end he directed downwardly and in a direction oppositeto the fabricfeeding direction, the stitch formed during the previouscycle being still held by the needle shank;

(C) Continuing the axial advance movement of the needle until itthoroughly pierces the knitted fabric, the hooked end being directedwholly downwards as in (A) above;

(D) Withdrawing the needle while simultaneously rotating it through 30degrees approximately so that its hooked end is directed downwards andin a direction concordant with the fabric-advance direction, so as totake the thread necessary for the formation of a new stitch;

(E) Continuing the needle-retracting movement and concurrentlycontinuing the rotational movement until an angular value of 45 degreesis attained so as to discharge the previously formed stitch;

(F) Continuing the needle withdrawal further so that its hooked endtakes from the thread-feeding device the amount of thread which isnecessary and sufficient for the formation of a new stitch;

(G) Bringing the needle back to its starting position.

As can be seen, and stated in simpler words, the improved inventivemethod for the formation of a loop stitch of the type Bureau ofStandards No. 101 comprises a sequence of combined movements of axialtranslation and axial rotation for the needle. It will be more clearlyappreciated, from the following detailed description of an exemplaryembodiment of this invention, how the subject method ensures absolutereliability in operation, while concurrently affording operationalspeeds which are by far higher than those which were permissible withprior art machines.

The foregoing and other objects, features and advantages of theinvention will become apparent to all those skilled in the art from theparticular ensuing description of an exemplary embodiment thereof, asillustrated in the accompanying drawings.

In the drawings:

FIG. 1 is a perspective partial view of a linking machine incorporatingthe inventive device.

FIG. 1a is a diagrammatical perspective view of a detail of the subjectdevice and shows the linkage intended to impart the axial rotarymovement to the needle bar.

FIG. 2 is an exteremely simplied kinematic diagram which is illustrativeof the movements of the several component parts of the subject devicealong with their mechanical interconnections.

FIGS. 3, 3a, 3b and 3c are diagrammatical illustrations to show therelative positions of the needle bar and the eccentric in correspondenceto the several angular positions of the latter.

FIGS. 4, 4a and 4b show, respectively three different needle shapeswhich can be adopted for use with the subject device, and

FIGS. 5, 5a, 5b and 5c are diagrammatical illustrations of thesequential steps of loop stitch formation.

Having initial reference to FIG. 1, there is shown a linking machine ofwhich only those members which are most significant and important forputting the instant invention into practice have been shown. There areshown the pin plate or ring 1, the needle-synchronization mechanism 2,the upper supporting arm 3 and the thread-guide 4. Said thread guide 4has been shown diagrammatically to simplify the showing and, inconnection with said member, it should be noticed that the thread guidehas an offset section 5, which extends parallel to the axis of guide 4,said section 5 having a through bore, as shown in the drawing, to allowthe thread to pass therethrough. The tip 5 of the thread guide 4 has amovement whose trajectory is a line, such as a circular line, anelliptical line, or an inverted-U line, according to the constructionalconvenience.

The description of the conventional component parts of a linking machinesuch as for operating the guide 4, is dispensed with herein, since theyare wholly familiar to those skilled in the art.

The needle 6 can be a hooked needle, a barbed needle or a latch needle.

These needle shapes are known but they are diagrammatically illustratedin FIGURES 4, 4a and 4b. The needle 6 is carried by a sturdy needle bar77; and said needle bar is mounted for rotation and axial slidingmovement within a needle carrying member 8. The latter is a lever whoseend remote from the needle is pivoted at 19 on a projection 20 onsupport 3 so as to be pivotal in a horizontal plane to shift the needlefrom one pin to the next (not shown) on plate 1. The end of the needlebar 7 remote from the end which directly carries the needle is fixed toa crank 11 (FIG. 1a) and, more exactly, with an end thereof. To theother end of the crank 11 is affixed a pin 11a which is limitedlyslidable within a spherical head 11b which, in turn, is slidably engagedwithin an almost closed cylindrical groove 13 formed in a small block12. Said block 12 is rigid with the right (as viewed in FIG. 1) end of alever 10. Said lever 10 is pivoted at its right end to a pin 15 affixedto an eccentric 17. The eccentric 17 is rotated about the axis of ashaft 18 which is driven by appropriate prime movers which are not shownherein, except for the motor illustrated diagrammatically as MOT in FIG.2. The connection between the right end of lever 10 and the pin 15 isnot a rigid one, but it should afford a certain clearance: to this endthere is provided a universal joint type connection indicated at 16 inFIG. 1. The pin 15 at its upper most end engages, with a certainclearance, in the forked end of a stirrup 14. The latter is fixed on topof the block 12. Finally, the lever 10, at its left end (as viewed inFIG. 1) is connected to a pin 9 which passes through the member 8 andwhich is slidable within a slot 9 formed on said member 8. Theconnection between the pin 9 and the lever 10 is not an entirely rigidconnection since a certain clearance is required for the satisfactoryoperation of this connection. Consequently, said connection(diagrammatically shown in FIG. 2 and indicated at 9a, and shown also inFIG. 1) is a universal joint type connection very much the same as theone shown for the connection 16 of FIG. 1 between the pin 15 and thelever 10. There are thus four flexible connections between the severalparts of the device. They are: the connection 9a, the connection 15-14,the connection 1516 and the connection 11a11b. These connections areessential for quiet operation and form an important feature of thepresent invention, by virtue of which the high-speed operation canproceed unhindered and with excellent results.

FIG. 2 of the accompanying drawings is a kinematic diagram to give aclear idea of the several movements of the subject device. In FIG. 2 themovements are symbolically shown by arrows and it is deemed fitting toexplain their meaning in advance before passing to the detailed analysisof the movements. In the drawing, the arrow f indicates a shortazimuthal movement (that is a movement which takes place entirely in ahorizontal plane) of the needle bar carrier 8. As outlined above, saidmovement, which is caused by the mechanism 2 (FIG. 1), consists of ashort angular stroke to cause the needle from one impaling pin to thenext on plate 1 as the linking stitches are sequentially formed. Thearrows f and f indicate reciprocal movements imparted to the members 8and 10, respectively. Also the arrow 3 indicates an angular azimuthalmovement of member 10 akin to that indicated by the arrow f but having agreater angular width. Lastly, the helical arrow indicates a rotationalmovement of the needle bar 7-7 about its own longitudinal axis.

It is convenient to examine FIG. 2 together with the already describedFIG. 1, the reference numerals being the same in the two figures. Thereis a block marked with the letters MOT which indicates a source ofmechanical power of any optional kind. The block MOT transfers a rotarydrive continually to the eccentric 17 via the shaft 18. Thus the lever10 receives a reciprocal drive (arrow 12;) along with an azimuthal drive(arrow i In other words, the movement of the lever 10 is a compositemotion, both reciprocal and rotational, which is somewhat similar to themovement of the crank and rod system. It is obvious that the movement ofthe lever 10 is imparted, as such, to the block 12 which is solidlyaffixed to said lever 10. Through the block 12,

the ball 11b, the pin 11a and the crank 11 the needle bar 7-7' receivesits forward drive (towards the pin plate 1) and its backward drive (awayfrom the pin plate). Said movements of the needle bar arediagrammatically indicated by the arrows f (reciprocation) and f(rotation). There should be noted, now, that the pin 9 and its universalconnection 9a cause the lever 8 to be swung about pin 19 whose axis isthe vertical axis XX of symmetry of the machine. This axis passes, dueto obvious geometrical reasons, through the center of the pin plate 1.By examining FIGS. 1 and 2 conjointly in the light of the foregoingconsiderations, it can be easily understood that, for every revolutionof the eccentric, the needle bar performs the combined motions of axialtranslation and axial rotation which cause the operational stepsindicated under the letters from A to C in the introductory portion ofthis specification.

These movements of the needle bar, along with the correspondingpositions thereof, can be clearly seen in FIGS. from 3 to 3c inclusive.FIG. 3 shows the back dead center position of the needle bar and saidposition will be assumed to be the starting position, or, as expressedin terms of polar co-ordinates, as the 0 position. The direction ofrotation of the eccentric 17 is assumed to be counterclockwise.

Likewise, FIG. 3a shows the 90 position, FIG. 3b the 180 position, andFIG. 30 the 270 position, whereafter the cycle is repeated as many timesas there are stitches to be made by the machine on the knitted fabric tobe linked. In FIGS. from 3 to 30 the relative positions of the needlebar, the block 12, the crank 11 and the lever can be very clearly seenand no further illustration should be required. However, in order tosupply those skilled in the art with the suggestions which are necessaryto put the invention into practice, the following table shows theseveral steps of the machine operation corresponding to the severalrotational positions of the eccentric, a few of which are shown in FIGS.3 to 30, the others being not shown.

Eccentric CONFIGURATIONS OF THE COM- position, deg. PONENT PARTS OF THEDEVICE 0 (FIG. 3) Needle at its back dead center. Rotation of thecrochet or hooked end of the needle=nil. The preceding stich has alreadybeen formed.

30 (approx.) The needle has been advanced and the needle is rotatedsince the axial rotation of the needle bar has already started.

The already formed preceding stitch is still being held by the needleshank.

90 (approx) (FIG. 3a)---- The movements indicated above are continuedand the needle has gone through its maximum angular stroke, the reversalof movement being now started.

180 The above listed movements are continued but the needle has alreadypenetrated the fabric.

210 (approx)--- The needle has gone back and the angular position of therod is about 30 in the direction opposite to the preceding one. Thethread for the next stitch is being charged, preparatory to casting offthe old loop.

240 (approx)--- The needle is pushed back and the angular position ofthe rod is about 45 as computed from the starting point of its axialrotation: thus the old loop can be cast off from the needle withouttrouble.

300 (approx)--- The needle is pushed farther back to take from thethread guide the amount of thread which is necessary for the formationof the following loop.

The angular (axial) position of the rod is not critical in this case.

360 The needle has been brought back to its starting point again and thecycle can be indefinitely repeated.

In summation, the needle bar has, by virtue of the inventive'device, notonly an axial reciprocation of conventional type, but also anoscillation of about It should be noticed that the angular amplitudeslisted in the above table are merely indicative and such is also thevalue of 90 for the rotation of the needle bar. What actually doesmatter is that these movements take place according -to the alreadyindicated sequence.

There remains now to be elucidated the function of the thread guide 5.In FIG. 1 said member has been diagrammatically shown and it has beensaid that said thread guide should have a tip 5 parallel to the axis ofsaid thread guide. The thread guide should have a circular or ellipticalmovement, or a movement in the form of an inverted U, as suggestedabove. The selection of said kind of movement depends on the particularconstructional convenience and anyone skilled in the art is in aposition properly to select the kind of movement (which can be obtainedwith means known per se within the perview of any skilled craftsman)which is most suited to any particular requirement. The means forobtaining said circular, elliptical or inverted U movements are notdescribed herein, nor are they shown in the drawings since they aregenerally well known and usually consist of cams, eccentrics and thelike whose faces will be properly designed.

The other parameters of the thread guide movements should be selectedwithin the purview of anyone skilled in the art according to theparticular case involved. By way of example only, if a simple circularmotion is selected, very satisfactory results are obtained, from thepoint of view of safety of thread loading if the circular motion isuniform, that is, its speed is constant and is two or three times asgreat as the stitching speed. This is merely an example, but it issufficient to show that, by adopting the inventive device, high speedscan be adopted both for stitching and feeding while still havingreliable operation on account of the extremely simple structure of themechanism described in the foregoing.

Referring to FIGS. 4, 4a and 4b, it will be sufiicient to say that theyshow a hooked needle, a latch needle and a barbed needle, respectively.

FIGS. 5, 5a, 5b and 5c illustrate with great simplicity and clarity theseveral loop formation steps performed by the device according to thepresent invention when employing a hooked needle.

It should also be noticed that this is the first time that a hookedneedle or, in general, a needle having a threadseizing protrusion hasbeen used in a linking machine having a needle internal to the pinplate. This is possible on account of the orderly sequence of movementsimparted to the hooked needle as exemplified herein (barbed or latchneedles could also be used, however) by the inventive device.

While the invention has been shown and described with reference to apreferred embodiment thereof, it will be understood by those skilled inthe art that many changes in form and details may be introduced thereinwithout departing from the spirit and scope of the present invention.

I claim:

1. In a hosiery linking machine comprising a ring carrying impaling pinsfor impaling the fabric to be linked, a needle cooperating with saidplurality of impaling pins internally of said ring, and a device forfeeding and guiding the thread, cooperating with said needle and saidpins own axis so that its hooked end is directed downfor the formationof the loop stitch, a stitch-forming dewardly and in a directionopposite to the fabric-feedvice comprising: ing direction, while thestitch formed during the previsaid needle having a projecting grippingmember adapted firmly to grip the thread fed by said thread-feeding andguiding device;

a needle-carrying member mounted to have a limited angular stroke abouta vertical axis located at the geometrical center of said ring;

a needle-bar fixed at one end to said needle and mountous cycle is stillheld by the needle shank;

continuing the axial advance of the needle until it is pushed throughthe knitted fabric and into operative relation with the thread-feedingdevice, while continuing to direct the hooked end of the needledownwardly;

withdrawing the needle from the fabric while simuled internally of saidneedle-carrying member so as to 10 taneously rotating it through 30degrees approxibe axially slidable therein, and to be rotatable aboutmately, so that its hooked end is directed downwards its axis during :astep of the stitch-forming sequence; and in a direction concordant withthe fabric-feed a lever mounted beneath said needle-carrying member;direction; an eccentric connected to said needle-carrying membercontinuing the needle-retracting movement and concurfor oscillating saidneedle-carrying member upon rorently continuing its rotational movementuntil an tation of said eccentric, to impart an axial translaangularvalue of 45 degrees is attained so as to cast tional motion to saidneedle-bar within said needlcoff the previously formed stitch;

carrying member; continuing the needle withdrawal further so as to takea prime mover internal to the machine for rotating said from thethread-feeding device the amount of thread eccentric, which is necessaryand suflicient for the formation a grooved block positioned on saidlever adjacent said of a new stitch; and

eccentric, and having therein a groove that extends bringing th needleba k to it tarting position.

parallel to the axis of said eccentric; 3. A device according to claim 1wherein said needle a pin having a spherical tip slidable within saidgroove is a cro het hook,

in said block, and 4. A device according to claim 1 wherein said needlea crank fixed at one end to said pin and at its other i abarbed hook dneedle,

end to the end of the needle-bar remote from said 5, A device accordingto claim 1 wherein said needle needle to impart rotary movement to saidneedle-bar is a hooked latch needle.

during the stitch forming sequence.

2. A method for the formation of a loop stitch in knit- References Citedted fabric mounted on a linking machine having a hooked UNITED STATESPATENTS needle mounted internal to the pm plate of the machine,

fabric feeding means, and a thread-feeding device, comprismg impartingthe following sequence of movements 35 1 3 12/1966 Matthews -L: 112 25to the needle bar and thus to the needle:

causing the needle to advance towards the pin plate from the insidethereof to the outside thereof with the hooked end of the needlepointing downwardly; rotating the needle through about 45 degrees aboutits MERVIN STEIN, Primary Examiner G. V. LARKIN, Assistant Examiner

